1. Technical Field
The present invention relates to semiconductor package structures, and more particularly, to a high-reliability semiconductor package structure.
2. Description of Related Art
Due to technological advancement, vehicular electronic systems are being rapidly incorporated into various types of vehicles. For instance, intricate and precise electronic circuit systems, such as vehicular inductive radar, vehicular hi-fi, and various vehicular safety systems are widely incorporated into and applied to various types of vehicles. However, EMC-related problems and voltage regulation-related problems which arise inevitably from electronic circuit systems are becoming more serious. For the details of the challenges posed by EMC or voltage regulation to the vehicular electronic circuit systems, refer to related international regulations, such as IEC7637 and JASO. DO-218(AB) published by the JEDEC is currently regarded as one of the recommended components for use in the solutions to EMC-related problems.
Referring to FIG. 1, a conventional DO-218(AB) package structure comprises a heat sink 401, a lead frame 402, a die 403, and a black glue 404. As indicated by its existing application and test data, the application of the conventional DO-218(AB) package structure is restricted to low-power EMC protection and low-power voltage regulation. But the conventional DO-218(AB) package structure cannot overcome the high power EMC impact requirements defined and regulated by strict regulations, such as IEC7637 and JASO-D001-94.
Referring to FIG. 2, the DO-218(AB) package structure fails to overcome the impact of high power EMC mainly because the heat generated from the die 403 is produced in a transient state (the instant when EMC occurs) and at a PN junction 405 of the semiconductor juncture of the die 403. Since the PN junction 405 and an insulating protective layer 406 of the die 403 must face upward (the insulating protective layer 406 of the die 403 cannot face downward, because if the insulating protective layer 406 faces downward, the insulating protective layer 406 will come into wide contact with the heat sink 401, thus deteriorating the production yield and causing severe component reliability-related problems), the lead frame 402 at the point of soldering cannot instantaneously and quickly absorb and dissipate heat dissipation; as a result, when subjected to the high-power EMC impact or operating in a high-temperature application environment, the products are confronted with serious malfunctioning-related problems. However, due to the rapid development and wide use of intricate vehicular electronic systems, the requirement set forth by IEC7637(IEC7637-2-5A, 5B) to require that protective components must be capable of enduring high-ampere current and long-term energy impact has already become a basic EMC requirement. In view of this, the structural specifications of the conventional DO-218(AB) package structure can no longer meet the demand for EMC or voltage regulation components of existing vehicular or industrial specifications.